5G BWP CSI Measurement Gap Selection Across Subcarrier Spacings

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Solution Overview

Problem

Existing 5G wireless systems face challenges in efficiently determining and reporting channel state information (CSI) for bandwidth parts (BWPs) due to varying subcarrier spacings, which affects downlink channel scheduling and resource allocation.

Innovation Solution

A wireless transmit/receive unit (WTRU) measures CSI in a target BWP during a measurement gap, determining the gap type based on subcarrier spacing and reporting the measured CSI in the current active BWP, using CSI-reference signals (CSI-RSs) to improve measurement accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the WTRU performs CSI measurements on a target BWP with different subcarrier spacing, then the downlink channel scheduling accuracy is improved, but the measurement gap requirements increase causing loss of time

Engineering Contradiction:
ImproveCSI measurement accuracyVSAvoidmeasurement gap duration
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies dynamics by making the measurement gap type adaptive based on the subcarrier spacing of the target BWP. When the target BWP has a larger subcarrier spacing than the current active BWP, a first measurement gap type is used; when it has a smaller subcarrier spacing, a second measurement gap type is used. This dynamic adjustment optimizes the balance between measurement accuracy and time loss by selecting the appropriate gap duration based on the specific measurement requirements of each BWP configuration.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the WTRU switches between BWPs with different subcarrier spacings, then the adaptability of downlink channel scheduling is improved, but the device complexity increases

Engineering Contradiction:
ImproveBWP switching capabilityVSAvoidmeasurement gap determination complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic adaptation by configuring the WTRU to automatically select between different measurement gap types based on the subcarrier spacing relationship between the current active BWP and the target BWP. This dynamic mechanism enables the system to adapt to various BWP switching scenarios without requiring complex manual configuration, as the appropriate measurement gap type is determined automatically through comparison of subcarrier spacing parameters.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent utilizes parameter changes by modifying the measurement gap type parameter according to the subcarrier spacing parameter of the target BWP. When the subcarrier spacing changes between BWPs, the measurement gap type parameter is adjusted accordingly (first type for larger SCS, second type for smaller SCS). This parameter-based approach simplifies the handling of BWP switching complexity by using well-defined parameter relationships rather than complex procedural logic.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4712651A2Method and WTRU for determining QCL parameters
Publication Date: 2026.03.18 INTERDIGITAL PATENT HOLDINGS INC
  • EP4712651A2 patent drawingFigure 1A
  • EP4712651A2 patent drawingFigure 1B
  • EP4712651A2 patent drawingFigure 1C

AI summary

Methods and systems are described herein for bandwidth part (BWP) operation in 5G wireless systems. A wireless transmit/receive unit (WTRU), configured with at least one bandwidth part (BWP), may receive a signal including an indication for the WTRU to perform measurements on a target BWP, which may be received as part of downlink control information (DCI) in the current active BWP. The WTRU may determine a measurement gap type based on at least one of a subcarrier spacing (SCS) of a current active BWP and a SCS of the target BWP. The WTRU may determine a measurement gap for the target BWP based on the measurement gap type. The WTRU may measure channel state information (CSI) in the target BWP during the measurement gap. The WTRU may send a report including the measured CSI in the current active BWP.